Field lighting apparatus for vehicular field working equipment



NUV- 16, 1954 H. E. KNoPP ETAL 2,694,773

FIELD LIGHTING APPARATUS PoR VEHICULAR FIELD WORKING EQUIPMENT FiledNov. 3, 1949 3 Sheets-Sheet 1 INVENTORS. HAROLD E KNGFP By FRANK G.MAJER Nov. 16, 1954 H, E. KNoPP ETAL 2,694,773

FIELD LIGHTING APPARATUS FOR VEHICULAR FIELD WORKING EQUIPMENT FiledNov. 3, 1949- 3 Sheets-Sheet 2 INVENTORS. ROLD E KNOPP 6, By FRANK G.MAJER NGV. 16, 1954 H E, KNOPP TAL 2,694,773

FIELD LIGHTING APPARATUS FOR VEHICULAR FIELD WORKING EQUIPMENT FiledNov. 3, 1949 3 Sheets-Sheet 3 INVENTORS. HAROLD E. KNOPP By FRANK G.MAJER United States Patent O FIELD LIGHTING APPARATUS FOR VEHICULARFIELD WORKING EQUIPMENT Harold E. Knopp, Chicago, and Frank G. Majer,Berwyn, Ill., assignors to International Harvester Company, acorporation of New Jersey Application November 3, 1949, Serial No.125,286

6 Claims. (Cl. 24U-7.1)

This invention concerns lighting systems for fieldworking implements andrelates more particularly to a lighting system wherein a light beamprojecting unit casts a beam with transverse sections of different rayintensity according to the distance the different sections areprojected, so as to cause substantially uniform illumination of theground intersecting pattern of the beam.

When headlight units of the conventional incandescent lamp type are usedupon fieldworking implements which are tilted for casting a light beamangularly downwardly on the iield there is non-uniform lightingintensity of the ground or plants intersected by different portions ofthe light beam. This undesirable condition prevails because the lightrays in the lower part of the divergingray beam strike the plants orground after projecting a shorter distance than will the rays in theupper part of such beam, and in the absence of proper correlationbetween ray intensity and angle of ray divergence the rays in the lowerpart of the beam do not spread so far as the rays adjacently to the topof the beam and produce greater illumination intensity in that part ofthe illuminated eld pattern nearer to the headlamp than farther from it.Also, with the conventional headlamp, side edge portions of the lightbeam are directed onto parts of the eld where they serve no usefulpurpose, thereby uselessly dissipating a substantial portion ofavailable light energy.

A general object of this invention is the provision of field lightingapparatus including a headlight unit which so controls the divergingangle of light rays that these rays are caused to diverge at a greaterangle in that portion of the beam which intersects the ground afterbeing projected a shorter distance and conversely decreasing thedivergence angle of the light rays in that portion of the beam which isprojected a greater distance before intersecting the ground. Betweenthese two extremes there is a gradient of light ray divergence whereforthe declining light beam will create a ground intersecting pattern ofsubstantially rectangular formation throughout which the illuminationintensity approaches uniformity.

' A more specific object is the provision of a iieldt lighting systemfor vehicular field-working equipment, employing a lighting unit capableof projecting a light beam wherein a main central part is substantiallyregular trapcziform in transverse section with the major base of thebeam disposed lowermost and which beam has a gradient of rayconcentration substantially in accordance with the altitude therein fromthe major base, to cause uniform intensity of ground illumination whenthe beam is directed in a declining position.

A further object is the provision of an improved tieldlighting apparatuswherein at least a pair of lighting units of the aforesaid type arearranged in tandem and so spaced from one another that the front portionof the ground intersecting pattern for the beam of the rearmost unitwill somewhat overlap the rearmost portion of the ground intersectingpattern of the beam projected from the forward unit.

Still another object is the provision of an improved mounting for thelighting units, wherein at least a portion thereof is mounted'upon theimplement in a fashion to decline the light beam toward the ground sothe illuminated portion of the eld will be caused to maintain a uniformposition with respect to the implement irrespective of changes inposition between the tractor and the implement articulately connectedtherewith. Using a 2,694,773 Patented Nov. 16, 1954 "Ice plurality oflight-issuing units with part on the implement has the advantage overside-mounted implements of avoiding tractor-mounted units near theoperator where their insect-attracting character is most annoying.

These and other desirable objects inherent in and encompassed by theinvention will be more readily comprehended from the ensuingspecification, the appended claims and the annexed drawings, wherein:

Fig. l is a plan view of field-working equipment consisting of a tractorand tillage implements together with lighting apparatus constructed inaccordance with the present invention mounted thereon.

Fig. 2 is a side elevational view of the equipment and apparatusillustrated in Fig. 1.

Fig. 3 is a transverse sectional view taken on the line 3--3 of Fig. 2illustrating-the cross-sectional configuration of a light beamand itsrelation to a lighting unit from which it is projected.

Fig. 4 is a plan view partly in section at a horizontal plane coincidingwith the principal axis of a headlight unit designed for projecting alight beam of regular trapeziform transverse section.

Fig. 5 is an enlarged rear elevational view of the lens of the lightingunit shown in Fig. 4, and taken at sub-- stantially the plane indicatedby the line 5 5 in Fig. 4.

Fig. 6 is a vertical sectional View taken diametrically through the lensshown in Fig. 5, substantially on the line 6--6 of Fig. 5

Figs. 7, 8 and 9 are vertical fragmentary sectional views takenrespectively on the lines 7-7, 8-8 and 9-9 of Fig. 5, illustrating flutetypes A, B and C.

Fig. l0 is a perspective view of a fragment of the lens in Fig. 5showing structural relation of adjacent liutes incorporated thereinto.

Fig. 1l is a rear elevational view of a modified form of lens cooperablewith a reflector of the type shown in Fig. 4 for creating a trapeziformlight ray beam.

Fig. l2 is a Vertical sectional view taken on the line 12-12 of Fig. ll.

Fig. 13 is a horizontal sectional view taken on the line 13-13 of Fig.ll.

Fig. 14 is an enlarged fragmentary rear elevational view taken on theline 14-14 of Fig. l2, illustrating one of the lens fillets.

Fig. 15 is a perspective view of that portion of the lens shown in Fig.14.

Fig. 16 is a sectional view taken on the line 16-16 of Fig. 14.

Referring now to Figs. l and 2, the vehicular fieldworking equipmentthere shown includes a wheel-type tractor 21 and implements 22 in theform of tool rigs disposed alongside of the tractor engine 23 atrespectively opposite sides thereof and connected with the tractor byparallel link assemblies 24 and a transverse tool bar 25. Each tool righas a vertical standard 26 secured thereto for supporting a horizontalbar 27 along which lamp mounting brackets 28 are mounted for adjustmentlengthwise of the tractor. The brackets respectively carry lightingunits 29a and 29b in such a manner that these units may be swung abouthorizontal axes to change the angularity of their light beams 31, 31aand 31b with reference to the ground surface 32. This pivotal adjustmentof the lighting units 29a and 29h changes the position of the light beampatterns Wa-Xa-Ya-Za and WIJ-Xb-Yb-Zb lengthwise of crop rows R. Abracket 33 secured to the left side of the tractor adjacently to theupper part of a radiator 34 pivotally supports a third lighting unit orheadlamp 29 for pivotal adjustment about a horizontal axis extendingtransversely of the tractor so that the beam 31 of this unit can also beadjusted lengthwise of its associated crop row R. The light beamprojected downwardly and forwardly from the light emitting unit on thebracket 33 has a rectangular ground pattern W-X--Y-Z.

Each of the light emitting units as 29 is constructed for projecting alight beam of inverted keystone shape, that is, having a transversesection of trapeziform, as illustrated in Fig. 3. This light beam isbounded by imaginary diverging lines M-N-O-P radiating from the unit 29.Since lighting unit 29 casts its beam 31 downwardly and forwardly, thediverging rays coincid ing with the lines M andv P will strike theground at opposite ends of the 'line which isof `the same length as theline XZ where the ground is struck by the light rays coinciding with thelines N and O which diverge at a lesser angle than theflines Maud P..The result is a lrectangular yground intersecting .pattern Z lfor the'beam 31. Unit 29 is so constructed that substantially .the same` number.of light rays are spread between .the lines N and i' as between thelines M and P wherefor the. light ray concentration. along the groundline WY Will Vbe substantially equal -to .the light ray concentrationand ground illumination along the line. XZ. This lighting unit is alsoconstructed so that there `is a` gradient of light ray concentrationsubstantially in accordance Awith the altitude from the major (lower)base of the .trapeziform beam from unit 29. Consequently there will besubstantially an equal density of light ray impingement throughout theground area WXYZ Units 29a and: 29h are constructed similarly to unit 29soA if they were mounted to decline their beams 31a and 31h at the sameangle as. shown for beam 31 the patterns We-Xa.-Ya-Za and Wfl-- XbYbZbwill also be rectangles.

h1 Figs. 4 to 110: therey is illustra-ted' a lamp unit operable to issuea light beam of regular trapeziforrn section as that illustrated at 31-in Figs. l, 2 and 3. This lamp unit comprises a pre-formedy glass lens4'1 fusionsealed at its periphery, as indicated at 42', to the rim of apreformed concave glass reflector section 43v to form therewith anenvelope 40 of the unit.

The concave inner surface 44 of the reflector section 43 is ofapproximately paraboloidal shape and is covered with a coating 45 of asuitable metal, such as aluminum for instance, to form a reflectingsurface. A concentratedV light source or larnent 46,` preferably in theform of a horizontally extending linear coil of tungsten wire, ismounted within thel envelope 40-y at approximately the focal point ofthe reflecting surface 45. The filament 46 is electrically connected toand is supported in place within the envelope by lead-in wires 47 which.extend through openings (not shown) in the wallV of the reflectorsection 43 at the rear thereof and are secured at their outer ends, as:by soldering for instance, to metal thimbles or' ferrules 48fusionsealed at their rims to the exterior of the reflector section1S-around the said openings. Metal contact or terminal lugs 49 aresuitably secured, as by soldering, to the closed ends of the metalthimbles 48y and are provided' with terminal screws 50 `for connectingthe lamp unit to a suitable source of current supply. f

The envelope 40 isl exhausted and, if: desired, filled` with a suitableinert gas such as argon, nitrogen, or mixtures` thereof, through anexhaust tubulation 51 at the apex of the reflector section 43, whichtubulationis afterwards tipped. off, as indicated' at 5,2, tohermetically seal the envelope.

As shown in Figs. and 6, the lens 41 is divided into a` series ofhorizontally extending primary flutes 53 for vertically spreading thelight rays from the unit. These horizontal flutes 53 are preferably ofconcave shape as shown in Fig. 6- and are of relatively large size.Thus, in thel particular case illustrated whereiny the lens 41 is of theorder of around 41/2 inches in outside diameter, the flutes 53 have avertical height of around 5/sinchl or soand arey curved to a radius ofthe order of from around 1% inch to 1 inch or thereabouts.

superimposed on eachI of the horizont-al1 primary flutes 53 is a seriesof vertically extending secondary flutes A, B, and C for horizontallyspreading the light rays from the lamp. The vertical? flutes A, B3 and Cmay be either of concave or convex shape, preferably 0f concave shape asshown, and are of relatively small size having, in the particular caseshown, a horizontal width of around V4 inch or so and bei-ng curved to aradius of the order of from' around 3A@ inch to 1/2 inch or thereabouts.

In accordance with the invention, each of the vertical flutes A, B, andC within each primary horizontal flute 53 is of progressively increasinglight spread throughout its vertical extent in order to horizontallyspread the resultant light beam therefromv throughout a wider angle atthe bottomv than at the top. For this purpose, each of theverticalflutes A B, and C is horizontally dividedv into a plurality ofvindividual flute seg- Holrliztlntel g t Flute Segment Spread' degreesA1, B1, Cl 12 A2, B2, o2..A 1s B3 24 A4, C3 32 It will be observed. thatflute A is horizontally divided into four individual flute segments A1,A2, etc. of more or less equivalent vertical extent while flutes B and Care divided into only three individual flute segments B1, B2, B3 and C1,C2, C3, with segments B3 and C2 of approximately twice the verticalextent of the other flute segments in each flute B' andv C. Thisdifference in the construction of the flutes A, B, and C is for thepurpose of obtaining greater uniformity in the distribution of the lightthroughout the beam pattern and to avoid dark spots therein.

Because of the progressively increasing horizontal spread of the variousvertical flutes, A, B, and C, the pattern ofthe resultant light beamfrom each of these secondary flutes is therefore of more or lessinverted keystone shape as shown in Fig. 3. The fin-al beam produced' bythe lamp as a Whole is the cumulative ef'- fect of the superimposedindividual light beams from the various vertical flutes A, B, and C,each individual beam being of a size corresponding to that of the finalbeam from the lamp.

The embodiment of lens structure illustrated in Figs. l1 through 16comprises a symmetrical concavoconvex circular lens 71 drawnsubstantially to scale and having a diameter of 4% measuring from theouter periphery of a flange 72 thereof.

This form of lens has a smooth convex front face 73. The rear face ofthe lens is traversed by a plurality of relatively broad horizontalflutes 74 for spreading the light rays vertically. Flutes 74 aretraversed by a plurality of fillets D for spreading, the rays of thelight beam horizontally. In Figs. 14', 15 and 16 it can be seen that thehorizontal curvature of the fillets D is graduated so as to decreasefrom a relatively long radius r at their upper ends to a shorter radiusr' at their lower ends to cause the light to be spread horizontally at awider angle near the lower ends of these llllets than adjacentl'y to theupper ends thereof. Consequently each of the fillets D causes the lightrays passing therethrough to be projected forwardly in d ivergingfashion as a beam of inverted keystone or regular trapeziform crosssection. These individual fillets are so arranged that the individualbeams cast thereby are superposed in substantially centeredregistration. at the distance from the lens to the geometric center ofthe ground illumination pattern which the unit is designed to produce.Consequently secondary beams cast respectively through the fillets Dcumnlatively produce, an inverted keystone sectioned composite beamresembling the shape illustrated in Fig. 3 and of course,` having thecombined illumination intensity of all ofthe secondary beams.

Having thus described. a preferred' embodiment of the invention with theview' of clearly and concisely illus- H trating, the same, we claim:

l. Field lighting apparatus for vehicular field-working equipment,comprising a beam casting lighting unit including a concave reflectoradapted to reflect light rays horizontally forwardlythereof insubstantial parallelism from a light source at a focal point of suchreflector, and a lens disposed in a plane transverse to the parallelrays within the open end. of the reflector' and having individualsegments intersected upon rear facesl thereof by respective groups ofsaid parallel rays, the rear faces of said segments'being concavelycurved from the top' to the bottom thereof to diverge the light raysvertically, said rear faces of the segments also being archedhorizontally and the radius of such arching being graduated from the topto the bottom of said faces to produce wider divergence of the lightrays horizontally at the bottom of said segments than at the topthereof, said lens segments being focused substantially upon a commonplane disposed transversely of the principal axis of the lens at apredetermined position forwardly thereof whereby the transverse patternsof the light ray beams directed forwardly through said segments whensuperposed at said plane form a composite transverse beam section forthe entire lens of substantially inverted keystone outline; a means formounting the unit on the equipment in a tilted position tilting thecomposite beam with its lower portion lowermost and at an angle causingthe rays in said upper and lower portions of said composite beam to havesubstantially equal transverse horizontal spread at a common groundlevel.

2. The combination set forth in claim 1 wherein there is a second ofsaid units, and means for mounting the second unit on the equipment intandem with the first unit and in a position correspondingly decliningthe light beam and at such distance from the first unit that the groundintersecting pattern of the second unit beam partially overlaps that ofthe first unit beam.

3. Field lighting apparatus for vehicular field-working equipment,comprising a beam casting lighting unit including a concave reflectoradapted to reflect light rays horizontally forwardly thereof insubstantial parallelism from a light source at a focal point of suchreflector, and a lens disposed in a plane transverse to the parallelrays within the open end of the reflector and having individual segmentsintersected upon rear faces thereof by respective groups of saidparallel rays, the thickness of said lens segments between said rearfaces and opposite forward faces thereof being graduated to be less at acenter portion of said segments than at upper and lower edges thereof todiverge the parallel light rays vertically as they emerge from theforward faces, said segments also having a thickness gradient betweenthe rear and forward faces thereof that varies symmetrically in oppositehorizontal directions from a vertical median line for each of saidsegments, and said gradient being more pronounced adjacent the loweredges of said segments than adjacent the upper edges thereof to causewider horizontal divergence of the rays as they emerge from the lowerfront face portions of the segments than the rays emerging from theupper front face portions, said lens segments being focusedsubstantially upon a common plane disposed transversely of the principalaxis of the lens at a predetermined position forwardly thereof to form acornposite light beam having a main central part which is substantiallyregular trapeziform in transverse section at said plane and having agradient of ray concentration substantially in accordance with altitudefrom the major base; and means for mounting the unit on the equipment ina position declining the beam with its major base lowermost and at anangle causing the rays along the major and minor bases to have asubstantially equal spread transversely and horizontally of the beam ata common ground level.

4. The combination set forth in claim 3, wherein there is a second ofsaid units, and means for mounting the second unit on the equipment intandem with the first unit and in a position correspondingly decliningthe light beam and at such distance from the first unit that the 6ground interesecting pattern of the second unit beam partially overlapsthat of the first unit beam.

5. Field lighting apparatus for a tractor and a eldworking implement,means for articulately htching the implement to the tractor toaccommodate relative movement therebetween attendant to traversal ofunlevel terrain, a beam casting lighting unit including a concavereflector adapted to reflect light rays forwardly thereof in substantialparallelism from a light source at a focal point of such reflector, anda lens disposed in a plane transverse to the parallel rays within theopen end of the reflector and having individual segments intersectedupon rear faces thereof by respective groups of said parallel rays, thethickness of said lens segments between said rear faces and oppositeforward faces thereof being graduated to be less at a center portion ofsaid segments than at upper and lower edges thereof to diverge theparallel light rays vertically as they emerge from the forward faces,said segments also having a thickness gradient between the rear andforward faces thereof that varies symmetrically in opposite horizontaldirections from a vertical median line for each of said segments, andsaid gradient being more pronounced adjacent the lower edges of saidsegments than adjacent the upper edges thereof to cause wider horizontaldivergence of the rays as they emerge from the lower front face portionsof the segments than the rays emerging from the upper front faceportions, said lens segments being focused to form a composite beamwhich when cast horizontally is relatively narrower transversely in itsupper portion than in its lower portion at common vertical transverseplanes spaced lengthwise of such beam and which possesses a rayconcentration which diminishes substantially uniformly from the narrowupper portion to the lower portion; and means for mounting the unit onthe implement in a tilted position declining the beam with its lowerportion lowermost and at an angle causing the rays in said upper andlower portions to have a substantially equal transverse horizontalspread at a common ground level.

6. The combination set forth in claim 5 wherein the implement is mountedbeside the tractor and the unit is mounted to project its beam forwardlyand downwardly, and wherein there is a second of said units, and asecond means for mounting the second unit on the tractor ahead of and intandem with the first unit, and the second mounting means being adaptedto retain the second unit in position for declining its light beamcorrespondingly to the declination of the first unit and at such adistance forwardly of the rst unit that a rear portion of the groundintersecting pattern of the second unit overlaps a front portion of theground intersecting pattern of the first unit.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,227,778 Gilson May 29, 1917 1,399,749 Conklin Dec. 13, 19211,459,268 Smith June 19, 1923 1,686,543 Wood Oct. 9, 1928 1,724,757 FreyAug. 13, 1929 2,154,842 Glenn Apr. 18, 1939 2,170,682 Frech et al Aug.22, 1939 2,304,365 McCormick Dec. 8, 1942 2,568,494 Geissbuhler Sept.18, 1951

